#include <reg51.h>

sbit SDA = P2^0;
sbit SCL = P2^1;

void iic_init();
void iic_start();
void iic_stop();
void iic_ack(unsigned char a);//a=0 ack  a=1 nack
char iic_write_byte(unsigned char byte);
unsigned char iic_read_byte(char ack);